<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style>
			div{width: 200px;height: 200px;border: 1px red solid;
			/* top上   right右    bottom下   left左 */
			    /* background-image: linear-gradient(to top left,red,blue,green,yellow); */
				background-image: radial-gradient(red,blue,green,yellow);
			}
		</style>
	</head>
	<body>
		<div></div>
	</body>
</html>
